title: The Sydney Blood Bank Cohort: implications for viral fitness as a cause of elite control.
abstract: OBJECTIVE
  The Sydney Blood Bank Cohort comprised eight individuals who were infected with an attenuated, nef/LTR-deleted strain of HIV-1 from a single donor. All six recipients with sufficient follow-up, as well as the donor, were long-term nonprogressors. Only three recipients have maintained undetectable plasma viral loads, allowing investigation of factors that determined elite control of attenuated HIV-1 infection.
  
  
  RESULTS
  Follow-up of recipients showed that infection with this attenuated HIV-1 strain resulted in either low or absent viral replication in vivo for up to 29 years. The three patients without detectable viraemia have been studied for virological, genetic and immunological correlates of elite control. CD4 proliferation in vitro in response to p24 provided the clearest distinction of elite controllers from the slow progressors. Host factors are believed to differentiate the three elite controllers; only one, C135, has identifiable genetic polymorphisms that probably contributed to nonprogression: Δ32 CCR5 heterozygosity, HLA-B57 and HLA-DR13 alleles, in addition to infection with nef-defective HIV-1.
  
  
  CONCLUSIONS
  Even nef-defective HIV-1 can lead to sufficient replication in vivo to enable viral evolution and eventual progression to immunodeficiency. Host factors modified the outcome of infection with attenuated HIV-1, as exemplified by the unique patient C135.
authors.affiliation: aCentre for Applied Medical Research, St. Vincent's Hospital, University of New South Wales, Australia. j.zaunders@amr.org.au
authors.forename: John
authors.initials: J
authors.lastname: Zaunders
authors.forename: Wayne B
authors.initials: WB
authors.lastname: Dyer
authors.forename: Melissa
authors.initials: M
authors.lastname: Churchill
mesh_terms: D001315:Australia; D001771:Blood Banks; D015331:Cohort Studies; D015658:HIV Infections / Q000821:virology*; D016325:HIV Long Terminal Repeat / Q000235:genetics; D020276:HIV Long-Term Survivors; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology*; D006801:Humans; D014774:Virulence; D014779:Virus Replication; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D054311:nef Gene Products, Human Immunodeficiency Virus